Answer:
1/6 is the probability of it being a green plastic marble.
Step-by-step explanation:
Note that there are 18 marbles in all (12 + 6 = 18).
Half of the green marbles (6) are made of plastic: 6/2 = 3
From the information above, we see that 3 green marbles are made of plastic. There are 18 marbles in all.
Divide, and simiplify.
(3/18)/(3/3) = 1/6
1/6 is the probability of it being a green plastic marble.
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